package com.exam.pay_local_sign.wxpay;

import java.security.MessageDigest;

public class MD5
{

	private MD5()
	{
	}

	public final static String getMessageDigest(byte[] buffer)
	{
		char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
		try
		{
			MessageDigest mdTemp = MessageDigest.getInstance("MD5");
			mdTemp.update(buffer);
			byte[] md = mdTemp.digest();
			int j = md.length;
			char str[] = new char[j * 2];
			int k = 0;
			for (int i = 0; i < j; i++)
			{
				byte byte0 = md[i];
				str[k++] = hexDigits[byte0 >>> 4 & 0xf];
				str[k++] = hexDigits[byte0 & 0xf];
			}
			return new String(str);
		}
		catch (Exception e)
		{
			return null;
		}
	}

	public static void main(String arg[])
	{
		String aaa = "appid=wxe54363deb2eeb75a&noncestr=UecTUnenFbtRphEeEie3yYf5UyzNpBJB&partnerid=1451534002&prepayid=wx201703301708260d20ffdedb0827363866&timestamp=1490864902&wxpackage=Sign=WXPay&key=shishuowxe54363deb2eeb75ashishuo";
		String sign = getMessageDigest(aaa.getBytes());
		System.err.println(sign);
	}

}
